Influence of Treads Groove, Hardness and Contaminants on the Slip Resistance of Outsole of High-Heeled Shoes

The aim of this study was to explore the interaction effects of hardness (75A, 80A, 90A), structures of tread groove (spacing, width, depth and orientation) and contaminants (dry, wet and vegetable oil) on coefficient of friction (COF) of TPU outsole of high-heeled shoe, by application the SATRA whole shoe tester with normalized ceramic tile. Results of univariate analysis show that (1) in the dry condition, orientation of tread groove was the main factor impacting the COF of TPU outsole; (2) ‘Orientation * contaminant', ‘Hardness * contaminant' and ‘Orientation * hardness * contaminant' had significant interaction impact on COF; (3) COF at the hardness of 80A was lower than that of 70A and 90A in the dry condition; while, those in the wet and oil conditions were controversial. Overall, variables of hardness, contaminant and orientation of tread groove were main influence factors in terms of slip resistance.